The field of the present invention relates to optical devices incorporating distributed optical structures. In particular, distributed optical structures exhibiting reduced optical loss are disclosed herein.
One or more distributed optical structures (i.e., sets of diffractive elements) in a channel waveguide, an optical fiber, a slab waveguide, or another guided-wave optical structure may be used in a variety of devices for spectral filtering, laser frequency control, spectral multiplexing, optical sensing, or other functions. It is often important that such devices operate with levels of optical loss at or below an operationally acceptable level. In some instances a distributed optical structure generates loss by coupling a portion of a guided optical signal into an unwanted cladding, free-space, or other mode, wherein the coupled optical power is dissipated without useful function. Distributed optical structures wherein the level of coupling between a signal optical mode and one or more loss optical modes (i.e., mode(s) not associated with the intended function of the device) is reduced, thereby reducing optical loss of the device, are disclosed herein.
Various embodiments, implementations, and adaptations of such diffractive element sets are disclosed in: application Ser. No. 10/998,185 filed Nov. 26, 2004 in the names of Dmitri Iazikov, Christoph M. Greiner, and Thomas W. Mossberg (now U.S. Pat. No. 6,993,223 issued Jan. 31, 2006); application Ser. No. 10/898,527 filed Jul. 22, 2004 in the named of Dmitri Iazikov, Christoph M. Greiner, and Thomas W. Mossberg (now U.S. Pat. No. 7,194,164 issued Mar. 20, 2007); application Ser. No. 10/989,244 filed Nov. 15, 2004 in the names of Christoph M. Greiner, Thomas W. Mossberg, and Dmitri Iazikov (now U.S. Pat. No. 6,961,491 issued Nov. 1, 2005); application Ser. No. 10/798,089 filed Mar. 10, 2004 in the names of Christoph M. Greiner, Thomas W. Mossberg, and Dmitri Iazikov (now U.S. Pat. No. 6,823,115 issued Nov. 23, 2004); application Ser. No. 10/989,236 filed Nov. 15, 2004 in the names of Christoph M. Greiner, Dmitri Iazikov, and Thomas W. Mossberg (now U.S. Pat. No. 6,965,716 issued Nov. 15, 2005); application Ser. No. 10/653,876 filed Sep. 2, 2003 in the names of Christoph M. Greiner, Dmitri Iazikov, and Thomas W. Mossberg (now U.S. Pat. No. 6,829,417 issued Dec. 7, 2004); application Ser. No. 10/229,444 filed Aug. 27, 2002 in the names of Thomas W. Mossberg and Christoph M. Greiner (now U.S. Pat. No. 6,678,429 issued Jan. 13, 2004); application Ser. No. 10/602,327 filed Jun. 23, 2003 in the name of Thomas W. Mossberg (now U.S. Pat. No. 6,859,318 issued Feb. 22, 2005); application Ser. No. 09/811,081 filed Mar. 16, 2001 in the name of Thomas W. Mossberg (now U.S. Pat. No. 6,879,441 issued Apr. 12, 2005). Each of said applications is hereby incorporated by reference as if fully set forth herein.